Significance of interplay between austenite stability and deformation mechanisms in governing three-stage work hardening behavior of phase-reversion induced nanograined/ultrafine-grained (NG/UFG) stainless steels with high strength-high ductility combinat

In the context of obtaining high strength-high ductility combination in nanograined/ultrafine-grained austenitic stainless steels, we underscore the dependence of grain structure and deformation mechanism. In high strength nanograined/ultrafine-grained steel, deformation twinning contributed to the excellent ductility and high strain hardening rate, while in the low strength coarse-grained steel, ductility and strain hardening ability was also good, but due to strain-induced martensite. The change in deformation mechanism with grain size is attributed to austenite stability-strain energy relationship.